Can work done by a body be negative or positive?
- Positive x-direction
- Negative x-direction
- Positive y-direction
- Negative y-direction
Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, is deflected by a strong magnetic field to your right side. What is the direction of magnetic field?
A bullet of mass is fired with the speed of , the mass of the gun being . The velocity of recoil is:
Why anticlockwise motion is positive and clockiwse motion is negative
1 N is the force which produces an acceleration of 1 ms−1 in a body of mass 1 kg.
An electron traveling north enters a region where the electric field is uniform and points North. The electron:
The magnitude of the magnetic field that will cause the electron to follow the semicircular path from A to B is?
How much force is needed to produce an acceleration of in a body of mass ?
A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is
(a) towards south
(b) towards east
When a footballer kicks a ball, the ball moves in the direction of applied force. The footballer also experiences a force on his leg which is equal to the force he exerted on the ball.
the football player did not hit the ball hard
velocity of ball is proportional to the force acting on it
We prefer to use a long spanner to loosen a tight nut.
- Its kinetic energy remains constant
- Its momentum remains constant
- Its speed remains constant
- Its velocity will change
A truck of mass 1000 kg moving with a velocity of 40 kmh−1collides with a tree and comes to stop in 5 s. What will be the force exerted by a car on the tree?
(-) 2222 N
(-) 2242 N
(-) 2000 N
If the key in the arrangement (Figure) is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are
(a) concentric circles
(b) elliptical in shape
(c) straight lines parallel to each other
(d) concentric circles near the point O but of elliptical shapes as we go away from it
Which of the following property of a proton can change while it moves freely in a magnetic field?
None of these
A wire carrying a current of is placed perpendicular to a magnetic induction of. The force on each of the wire is
A force of acts on a particle of mass . Find the acceleration of the particle.
- Remain unaffected
- Speed up along the X direction
- Start moving in the Y direction
- Start moving in a circular path in the X-Y plane
- Down, into the page
- Up, out of the page
- 4 N
- 8 N
- 12 N
- 16 N
- It can change the direction of motion of the object.
- It can change the speed of the object.
- It can change the shape and size of the object.
- It can change the material and colour of the object.
A uniform magnetic field exists in the plane of paper pointing from left to right as shown in the figure. In the field, an electron and a proton move as shown. The electron and the proton experience?
- Forces both pointing into the plane of the paper.
- Forces both pointing out of the plane of the paper.
- Force pointing into the plane of the paper and out of the plane of the paper, respectively.
- Force pointing opposite and along the direction of the uniform magnetic field respectively.